Flashing reflector system

ABSTRACT

A flashing reflector system in which at least one retroreflective reflector having at least one wide angle area thereon is mounted on one side of a revolvable wheel member. When this assembly is revolved, a characteristic, highly visible flashing of retro-reflected light is produced which is visible over wide side angles relative to the revolving wheel member.

United States Patent [1 1 Golden et al.

[ FLASHING REFLECTOR SYSTEM [75] Inventors: Gerald Golden, HighlandPark;

James D. Kennedy, Streamwood, both of 111.

[73] Assignee: Beatrice Foods Company, Elgin, Ill.

[22] Filed: Feb. 19, 1974 [21] Appl. No.: 443,476

Related U.S. Application Data [63] Continuation-in-part of Ser. No.355,796, April 30,

1973, abandoned.

[52] U.S. Cl. 350/99; 350/103; 350/102; 40/138 [51] Int. Cl. G02b 5/12[58] Field of Search 301/37 R, 37 SA; 40/138, 40/139; 350/97-109 [56]References Cited UNITED STATES PATENTS Fike 350/99 1 June 3, 19753,541,606 11/1970 Heenan et a1 350/103 Primary Examiner-Alfred E. SmithAssistant Examiner-Michael J. Tokar Attorney, Agent, or Firml-lill,Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT Aflashing reflector system in which at least one retroreflectivereflector having at least one wide angle area thereon is mounted on oneside of a revolvable wheel member. When this assembly is revolved, acharacteristic, highly visible flashing of retro-reflected light isproduced which is visible over wide side angles relative to therevolving wheel member.

5 Claims, 33 Drawing Figures FLASHING REFLECTOR SYSTEM RELATEDAPPLICATION This application is a continuation-in-part of our earlierfiled US. Pat. application Ser. No. 355.796 filed Apr. 30, 1973 and nowabandoned.

BACKGROUND OF THE INVENTION It has now come to be generally recognizedthat bicy cles need to be equipped with reflective devices adapted toprovide a reasonable level of recognition and identification atnighttime under illumination of the active headlamps of a motor vehicleover an extreme wide angle relative to the position of such headlamps toreflective devices associated with a bicycle in motion. One of the majordeficiencies involving the use of prismatic reflectors on bicycles hasbeen the narrow reflectance angle commonly associated with such devices.

Even though positioned on the side or rear of a bicycle. so-called blindspots" were frequently left which made the bicycle operator more or lessunprotected from the standpoint of the operator of a moving motorvehicle approaching a moving bicycle at night. Indeed, when presented atcertain angles. bicycles equipped with older types of prismaticreflectors appeared to have no reflectors at all.

Recently, governmental authorities have recognized that reflectors canbe manufactured which provide retroreflection at wide side angles up toabout 50 or even more with respect to either side of a vertical theretoas compared with the previous retroreflectors of the molded plastic typewhich provided retroreflection at standard angles of only about +30 oneither side of a vertical thereto.

BRIEF SUMMARY OF THE INVENTION The present invention is directed to aflashing reflector system wherein at least one so-called wide angleretroreflector is mounted on a wheel member. A wide angle retroreflectorused in this invention is preferably of single-piece, integralconstruction, and is typically formed of molded plastic. Suchretroreflector is adapted to receive and retroreflect light raysreaching the reflector from any position within an extremely wide anglepreferably ranging from at least about 30 up to at least about 50 oreven higher on at least one side of the reflector relative to a verticalthereto.

The wheel member can be of any conventional type, but preferably is ofthe spoked type used generally on foot powered and two wheeled vehiclesincluding bicycles, tricycles, motorcycles. and the like.

The system of the present invention is adapted to provide in combinationwith a vehicle a system which produces distinct. strong flashes ofretroreflected light in various side regions around such vehicle as itmoves. The system uses at least one wide angle retroreflective surfaceper wheel member, and preferably each side of a given wheel member hasmounted thereon at least one retroreflective reflector having sideviewability from at least one side thereof. Typically. each such wideangle retroreflective reflector comprises at least two wide angleretroreflective surface portions, one portion being retroreflective atan angle which diverges relative to the other thereof.

One or more wheels of a given vehicle may be so equipped with such areflector. All of the side viewable wheel mounted retroreflectorsemployed may be mounted on a single wheel. It is preferred to use bothwheels in a two wheel vehicle. so that the front wheel and the rearwheel are each equipped with a wide angle reflector on each opposedwheel side thereof. Each reflector may be mounted at virtually anyposition or location desired on the side of a wheel member.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. 1 is a side elevational view of a bicycle whose wheels have mountedthereon wide angle retroreflective reflectors;

FIG. 2 is a top plan view of one embodiment of a retroreflectivereflector adapted for use in the present invention;

FIG. 3 is a vertical sectional view through the embodiment of FIG. 2with diagrammatic lines showing representative paths of incident andreflected light beams striking such reflector;

FIG. 4 is a view similar to FIG. 2 but showing another embodiment of aretroreflective reflector adapted for use in the present invention;

FIG. 5 is a view similar to FIG. 2 but showing another embodiment of aretroreflective reflector adapted for use in the present invention;

FIG. 6 is a view similar to FIG. 2 but showing another embodiment of aretroreflective reflector adapted for use in the present invention;

FIG. 7 is a view similar to FIG. 2 but showing another embodiment of aretroreflective reflector adapted for use in the present invention;

FIG. 8 is a view similar to FIG. 2 but showing another embodiment of aretroreflective reflector adapted for use in the present invention;

FIG. 9 is a view similar to FIG. 2 but showing another embodiment of aretroreflective reflector adapted for use in the present invention;

FIG. 10 is a side elevational view of the reflector of FIG. 9 mounted onthe spokes of a bicycle wheel adjacent the rim thereof;

FIG. 11 is a perspective view of a pin suitable for use in themanufacture of a centrally reflective prismatic surface in aretroreflective reflector of the present invention;

FIG. 12 is a top plan view of four pins of the type shown in FIG. 11 inan aligned configuration;

FIG. 13 is a top plan view ofa single wide angle retroreflectivereflector having integrally formed therein two wide angle reflectivesurfaces;

FIG. 14 is a plot in polar coordinates illustrating the type ofcharacteristic patterns of retroreflectance achieved using the reflectorof FIG. 13;

FIG. 15 is a top plan view of a retroreflective reflec tor havingintegrally formed therein left hand and right hand wide angleretroreflective surfaces and standard retroreflective surfaces;

FIG. 16 is a view similar to FIG. 15 but showing an alternativearrangement for the wide retroreflective reflector surfaces therein;

FIG. 17 is a plot in polar coordinates illustrating the type ofcharacteristic patterns of retroreflectance achieved using either thereflector of FIG. 15 or FIG. 16;

FIG. 18 is atop plan view of a single wide angle retroreflectivereflector having integrally formed therein single wide angle reflectivesurfaces;

FIG. 19 is a side elevational view of a bicycle whose wheels ha\emounted thereon the wide retroreflective reflector of FIG. I8;

FIG. 20 is a vertical sectional view horizontally taken through thereflector of FIG. 18 with diagrammatic lines showing paths of incidentand reflected light beams striking such reflector;

FIG. 21 is a schematic. diagrammatic representation of the type of lightpattern generated when the reflector of FIG. 18 is revolved as on awheel ofa bicycle of FIG. 19 as respects the eye of a viewer located ata retroreflective viewing angle with respect to such revolvingreflector:

FIG. 22 is a top plan view of a single retroreflective reflector havingintegrally formed therein left hand and right hand wide angleretroreflective surfaces and stan dard retroreflective surfaces;

FIG. 23 is a schematic representation of the reflector of FIG. 22illustrating a series of orientation planes between 0 and 90;

FIG. 24 is aside elevational view of one cube corner in a molded.transparent retroreflective reflector body made from a mold which isformed using the pins of FIGS. ll and 12;

FIG. 25 shows plots in polar coordinate of the characteristicretroreflective light pattern produced by each of two different facetpluralities in a standard reflector body of the type having cube cornersas illustrated in FIG. 24;

FIG. 26 is a series of plots in polar coordinates illustrating themanner in which the field of reflected light patterns change in a moldedtransparent reflector body as the axes of the pins employed are angledfrom a vertical positions as illustrated in FIG. 25 to position inclined to the vertical;

FIG. 27 shows illustrative plots of intensity versus incident angle fora reflector of the type having both standard reflector facets (orsurfaces) and wide angle reflector facets (or surfaces);

FIG. 28 is a plot illustrating the relationship between angle ofreflected light and intensity of reflected light at such angle bothhorizontally and vertically for a combination of wide angle and standardreflectors in a single reflector body;

FIG. 2) is a plot in polar coordinates showing curves illustrative ofthe type of retro-reflectance produced by a reflector equipped with onesection of standard type retro-reflective facets [or surfaces);

FIG. 30 is another plot in polar coordinates showing further curvesillustrative of the type of retroreflectance produced by a reflector.such as the reflector of FIG. 22 equipped with two sections of standardtype retro-reflective facets (or surfaces). each section having a [80opposite pin orientation relative to the other thereof. and with thewide angle reflective surfaces opaqued;

FIG. 31 is another plot in polar coordinates but showing curvesillustrative of the type of retro-reflectance patterns produced by areflector equipped only with wide-angle retroreflective facets (orsurfaces) produced by a reflector. such as the reflector of FIGv 22.with standard type retroreflective facets (or surfaces) opaqued and onewide angle side reflector opaqued as shown by the shaded lines in FIG.22;

FIG. 32 is a plan view of a bicycle equipped with an illustrativeembodiment of a retro-reflective flashing system of this invention; and

FIG. 33 is an isometric. diagrammatic view of the center plane ofa wheelmember illustrating the manner which a reflector used in this inventionis positioned and mounted thereon.

DETAILED DESCRIPTION Turning to the drawings. there is seen in FIG. 1 abicycle 29 equipped with different reflector assemblies numbered.respectively. as 30. 31. 32, 33 and 34. each such reflector being aretroreflective reflector having at least one wide angle reflectivesurface or area. Reflectors 30 and 31 illustrate suitable positions uponthe sides of a bicycle wheel member 27 or 28 respectively. wherereflectors incorportating wide angle retroreflective surfaces may bepositioned and mounted in the practice of this invention.

Referring to FIGS. 2 and 3. there is seen an embodiment of aretroreflective reflector suitable for use in the present inventionwhich is herein designated in its entirety by the numeral 35. Thereflector 35 is seen to comprise a panel 36 of lighttransmittingmaterial, such as acrylic plastic. or the like. The panel 36 has anouter face 37' and an inner face 38, the inner face 38 being ingenerally spaced relationship to the outer face 37. The panel 36 has aninturned. circumferentially extending flange 39 formed about theperiphery thereof. Flange 39 abuts against a flat base member 41 whichhas spaced, parallel faces. and which is opaque. the base member 41being conveniently formed of an opaque plastic material. such as an ABSresin. or the like. The rim of flange 39 is conveniently secured to thebase member 41 by any convenient means. such as sonic welding. adhesive.or the like. as those skilled in the art will appreciate.

The outer face 37 of panel 36 is generally smooth, generally continuous.and generally flattened. but the inner face 38 thereof has formedtherein a plurality of retroreflective prismatic surfaces. Thisplurality of prismatic surfaces is arranged into at least three zones orareas in the inner face 38. these zones being numbered foridentification purposes as 42, 43 and 44.

Zone 42 comprises prismatic surfaces adapted both to receive and toretro-reflect parallel rays of light striking the outer face 37 at afirst zone angle with respect thereto ranging from about 60 up to about90 (90 being vertical 47'. commonly alternatively ex pressed as 30 oneither side of vertical 47). The included angle marked 46 in FIG. 3illustrates a first zone angle of about 60 to 90 (or 30 to either sideof the vertical axis 47 of reflector 3S Zone 43 comprises prismaticsurfaces adapted to receive and to retro-reflect parallel rays of lightstriking the outer face 37 at a second zone angle with respect thereto.ranging from about 20 to about 75 (preferably from about 30 to 75). 90being vertical 47 as before. commonly alternatively expressed as to l5on either side of vertical 47.

Zone 44 comprises prismatic surfaces adapted to re ceive and toretro-reflect parallel rays of light striking the outer face 37 at athird angle with respect thereto. which is complimentary with. andopposed to. the second zone angle. Thus. parallel rays of light strikethe outer face 37 of the zone 44 at a third angle ranging from about 20to about (preferably from about 30 to 75) and reflect retroreflectivelysuch incident rays back.

Those skilled in the art will appreciate that a reflector 35 may containmore than three zones of prismatic sur faces. For example, in FIG. 4,there is seen a reflector designated in its entirety by the numeral 48which is similar to the reflector 35 except that the reflector 48 hastwo sets of central prismatic reflector areas desig nated, respectively,as 49 and 51, and four wide angle or side reflector areas designated,respectively, as 52, 53, 54 and 55. The reflector areas in FIG. 4 whichare viewable from the left-hand side (when frontally viewing a reflector48 as shown in FIG. 4) are the reflector areas designated 53 and 55which are marked by a left pointing arrow; similarly, the reflectorareas viewable from the right-hand side are the reflector areas numbered52 and 54 which are marked with a right pointing arrow. Such an arrowscheme for the side viewable reflector areas is also employed in each ofFIGS. 5 and 6 for the reflectors 57 and 58, respectively, shown in theseFIGS. 2, 7, as well as in FIGS. 8, 9, 13, 15,16, 18 and 22. Thoseskilled in the art will appreciate that it has heretofore been common inthe retroreflective reflector art to employ one or two zones or areas ofreflex reflectors, such as 49 and 51, for central or so-called standardviewing. Sometimes, one may slightly curve outwardly the central portionor area of such a reflector, such as is shown, for example, in FIG. 3,in an effort to avoid a problem of specular reflection, as those skilledin the art appreciate, but usually these areas are flattened.

While a wide angle reflector area, such as areas 43 and 44 in reflector35 of FIG. 2, commonly has side viewing angles, such as included angles59 and 61, as shown in FIG. 3, for left side and right side reflection,respectively, it is sometimes desirable to intensify the retroreflectedlight from each of these regions or angles 59 and 61, and such anintensification is achieved by using the two sets of side reflectorareas 52, 53, 54 and 55, such as illustrated in the reflector 48, areas52 and 54 being like area 43 but totalling together a larger surfacearea than area 43, and areas 53 and 55 being like area 44 but totallingtogether a larger surface area than area 44.

In place of the circular configuration employed in the reflector 35 andin the reflector 48, one can use an elongated arrangement, such as isillustrated by the reflectors 57 and 58. Reflector 58, for example, isadapted for affixing to the front, rear or sides of a bicycle,especially the wheels thereof. The reflective device 58 is suitable formounting so that a plane corresponding to its reflective surface (whichis perpendicular to its zero optical axis or perpendicular) is parallelto the center plane of the wheel or a plane tangent to the conical spokecage on either side of the wheel. Such a wheel side mounted reflectivedevice is preferably adapted not to interfere with any wheel adjustmentor to cause or aggravate wheel imbalance. The reflector 57 is suitablefor use on the side, front or rear of a bike, as well as on the wheelsthereof, as shown by the curved, longitudinal, peripheral edge thereof.

Reflectors, such as 35 and 48, are each adapted for use as side, frontor rear reflectors in addition to wheel mounting, with reflector 48being a preferred embodiment. Preferably such a mounted reflector 35 or48 is not obscured by a cyclist or his clothing.

FIGS. 7 through I0 illustrate various other embodiments of reflectors ofthe present invention. These embodiments demonstrate that one cancombine into a single reflector suitable for use in the teachings of thepractice of the present invention at least two different reflectingareas (zones), a central zone and a pair of side zones (or wide anglezones), the latter being op posed as respects each other so as to permita given reflector to be viewable from an extreme angle on opposed sidesof a reflector.

The side reflecting zones (or wide angle zones) may be definable asseparated or adjacent regions. or the side zones can be continuous withthe differences defining two zones being apparent by the angle at whichlight striking such a zone is retro-reflectively reflected. For example,in FIG. 8 the side reflector is in the nature of segmentalized diskwhich continuously extends circumferentially about a centrally located,centrally retroreflective reflector element. In this FIG. 8 embodiment,the segments define two different zones when viewed from opposedcomplimentary sides of the re flector shown, as shown by the arrows.

The central, or so-called standard retroreflective, reflector region ispreferably centrally located in a reflector body used in this inventionif such surfaces are pres ent. The arrows in FIG. 7 indicate sideviewability as is done in FIG. 4.

To enhance side (wide angle) viewability, the size (wide angle) of theside viewable reflex reflective zone in a reflector may be enlarged, ashas been done, for ex ample, in FIG. 9 at the expense of the centrallyview able (standard) area. A circular type of reflector, such as shownin FIG. 9, may be mounted on a bicycle wheel as shown, for example, inFIG. 10.

The side viewable (wide angle) reflector regions may be slightly spacedfrom the centrally viewable reflector regions, as is illustrated, forexample. in FIG. 7. Alternatively, the side viewable (wide angle)reflectors may be mounted in a circumferentially spaced but adjacentrelationship such as is illustrated in FIG. 8, the respective reflectorassemblies of FIGS. 7 and 8 each being adapted for use on a bicyclewheel, as for mounting on the spokes, or the like, using the clips shownon opposed side regions thereof.

As indicated above, it is preferred to use a centrally viewablereflector region (or zone or grouping) which has a viewing angle ofapproximately 30 on either side of the vertical. The side viewablereflector regions (or zones or groupings) are then chosen to havepreferably viewing angles of from at least about 30 on up at least tosome angle, such as about 56, etc., so as to compliment the centrallyviewable (standard) reflec tor.

In accord with the teachings of this invention, when a reflector withwide angle, side viewable reflector regions as described herein ismounted on a wheel, and such reflector is rotated with the wheel, thereflector seems to flash as each individual zone or grouping ofreflecting surfaces comes into a position where it reflects lighttowards the eye of the viewer as that zone rotates on the wheel. Theeffect is to heighten the ability of a reflector used in this inventionto be visible (detactable) to the eye of a viewer, such as a motorist inan approaching automobile as respects a bicycle.

Reflectors used in the present invention wherein three different zonesof reflectors are formed in the inner face of a light reflecting panelof light transmitting material are made in molds. As those skilled inthe art appreciate. the centrally viewable reflecting Zones employed inthe reflectors used in the present invention are made in a mold formedby using a hexagon-ally sided pin formed of steel, or the like, of whichthe pin shown diagrammatically in FIG. I] is illustrative Such pinscurrently commercially available typically have a dimension of about0.094 inch from one flat side to the next. Such a pin is ground on oneend thereof so as to have three faces defined about a common axis 60.Each face has a polished surface, as those skilled in the art willappreciate.

The side viewing elements may likewise be formed of hexagon-ally shapedpins. After making side viewable and centrally viewable pins, the pinsare set up into a configuration as desired and mounted together into abundle with the aid of a pin clamp. After the completion of such aclamping operation. it is convenient to electroform a mold having areflector-forming surface over the clamped pins, the clamped pinsserving as a master element for the electroforming operation. Theelectroforming operation is typically carried out by using stainlesssteel pins and nickel or the like as the electrodepositing metal, so asto be able to remove the electrodeposited metal from the master, andthereby to permit reuse of the master to permit separation of theelectrodeposited metal from the pins easily and conveniently. After themaster is removed, and the resulting nickel die has been built up with abacking to a thick ness as desired, a die may be shaped and machined.Thus, one can prepare separate dies for the centrally viewable reflectorprismatic surfaces and separate dies for the side viewable surfaces.Finally, the three differ ent types of elements, if all are to be usedin a single reflector. are assembled into a mold, and reflectors aremade therefrom.

The relationship between a group of facets in a conventional so-calledstandard retroreflective reflector (which, characteristically, isconsidered to be adapted to retroreflect impinging incident light overangles of about i usually horizonally). and a group of facets in aconventional so-called wide-angle retroreflective reflector (which,characteristically, is considered to be adapted to retroreflectimpinging incident light over angles ranging from not less than about 30of up to at least about 45 in one direction, usually horizontally) isillustrated, for example, by FIGS. 11, 12 and 24 through 28. In themanufacture of retroreflective reflector elements of such conventionaltypes, which are incorporated into the systems of the present invention,a plurality of so-called pins 70 may be employed. Each pin 70, as shownhere, is hexagonally shaped. The transverse distance between pin 70 flatsides is variable, but is typically of the order of about 0.094 inches,while the distance between opposing edges is also variable, but istypically of the order of about 0.108 inches. Three facets 71, 72 and 73are formed at the forward end of each pin 70. Each facet 71, 72 and 73traverses two sides ofthe hexagonal pin 70 and has an apex coincidingwith the axis 60 of each pin 70. Each facet 71, 72 and 73 has an anglerelative to the axis 74 of about A degrees.

To make a reflector, a plurality of pins 70 are arranged with theirrespective faceted heads grouped into a pattern. such as shown, forexample, in FIG. 12, and an electroform mold, or the like, is madetherefrom, as indicated above, using such pin pattern. An electroformmold is currently made. as indicated, by electroplating nickel or thelike onto and over a pin pattern. In such process, the high points andthe low points, respectively, over such a group of pins 70 are reversedin mirror image fashion in the product electroform mold over theirrespective positions in the pin 70 pattern. as those skilled in the artwill appreciate. From the product mold, a transparent, plastic reflectorelement is moldable. A section through one molded facet in a resultingreflector so made is shown, for example, in FIG. 24.

When such reflector body having such a plurality of individual facets,such as shown, for example, in FIG. 24, is caused to retroreflectincident light, a characteristic plot of reflectance angle versus lightintensity results, such as illustrated by the solid line 68 in polarcoordinate plot shown in FIG. 25. If one rotates the pins 70 of FIG. 12through l80 and makes a mold, and then a reflector, such reflector has apattern of reflected light, such as shown by the dotted line 69 of FIG.25. However, when one tilts the axis of each pin 70 (see FIG. 11) of aplurality thereof arranged in a pattern or assembly such as shown. forexample, in FIG. 12, from the vertical position shown in FIGS. ll, 12and 24 through increasing angles of common inclination rela tive to pinaxes 74, there is produced a family of characteristic plots ofreflectance angle versus light inten sity, such as shown in FIG. 26,each succeeding plot 76, 77 and 78 representing a greater commoninclination angle for each of a group of such pins 70, which areelcctroformed into a mold, and then the mold used to make a reflectorbody. When one tilts the axes 60 of such a plurality of such pins 70 inthe opposite direction, there is then produced a changing family ofcharacteristic curves 76, 77, 78, like those in FIG. 26, but reversed byl80 (not shown). The plots of FIGS. 25 and 26 are not for any specificreflectors, but are given herein to illustrate the known principlesinvolved.

When one combines into a single reflector body both the type of reflexreflectance shown in FIG. 26 with the type shown in FIG. 25, there isproduced in a single reflector body both such types of reflexreflectance. The reflector area shown in FIG. 25 is sometimes known as"standard" reflectance, which has a characteristic maximum reflectancevalue generally at 0 and which retroreflects incident light over anangle of about :30 on either side of a vertical or perpendicularthereto. The reflection area shown in FIG. 26 is sometimes known as wideangle reflectance, which has a characteristic maximum reflectance valuewhich can range very widely such as from about 10 to 88 on one side of aperpendicular thereto, though values between about 25 and 70 areparticularly and preferably useful. Such a reflectance as shown in FIG.26 retroreflects incident light through extreme angles on one side of avertical thereto, typically from about 8 to 88", though values betweenabout 30 and 50 are currently commercially particularly and preferablyuseful. To achieve horizontal side (wide angle) viewability in both leftand right directions, of course, two different groupings of preferablyidentical wide angle facets are commonly used, one group having pin axesreversed relative to the other.

A combination reflector body including both standard and wide anglereflectance displays a characteristic plot of retroreflectance angleversus reflected light intensity, as shown, for example, in FIG. 27 byillustrative curves 79, 80 and 81 wherein the curve 80 is produced by acombination of both of the so-called standard" retroreflective facets(surfaces) of FIG. 25. The curve 79 is produced by the so-calledwide-angle retroreflective facets (surfaces) sensitive to light on theleft side of the ordinate 82 (such as in FIG. 27), and the curve 81 isproduced by the so-called wide-angle retroreflective facets sensitive tolight on the right side of the ordinate 82. If, for example, the numberof standard facets in a given reflector is increased, the amount ofreflected light therefrom increases, and there is pro duced areflectance curve, such as, for example, the dotted curve 83. If, forexample, both the number of wide angle facets and their respectiveangles of inclination are increased equally for both right and leftmembers, the type of dotted reflectance curves 84 and 85, respectively,result. For example, current US. federal government standards for abicycle reflector comprising such a combination of left and right anglereflector facets in further combination with standard reflector facetsare illustrated in FIG. 28 where, for specific degrees of reflectancehorizontally or vertically measured, a corresponding intensity incandlepower per foot candle of reflected light is indicated, Bycombining different pin 70 groupings at different respective pin axis 60angles, as those skilled in the art will appreciate. one can produce analmost unlimited gradation of retroreflectance characteristics in agiven retroreflector, so that any given desired reflector type, or setof reflectance characteristics, can be produced in a given reflector byone skilled in the art within the limitations of pins, materials ofconstruction, design standards, and the like, using known technology.

In FIG. 29 is shown in polar coordinates a family of curves showingretroreflected light characteristics for one embodiment of a standardretroreflector wherein a plurality of pins (and, consequently, facetsmolded in the back of the reflector surface) are oriented in the mannershown, for exmaple, in FIG. 12. Observe that, in the region next to theorigin, a small zone of 100 percent reflectivity is provided, and, asone moves radially outwardly, the percentage (or efficiency) ofretroflectance drops, as shown.

In FIG. 30 is shown a family of retroreflected light curves in polarcoordinates for another embodiment of a standard retroreflector. such asthe reflector of FIG. 22, which is equipped with two sections ofstandard type retroreflective facets, each section having a l80 oppositepin orientation relative to the other thereof, but wherein, for presentpurposes, the wide angle reflective surfaces thereof (marked with thearrows shown in FIG. 22) are opaqued. Each of the two different groupsor sections are each comprised ofa plurality of pins (and, consequentlyfacets). One such section of pins (or facets) is oriented as shown inFIG. 12, while the second such section is oriented as though the FIG. I2pins had been rotated through 180. Observe that, with this type ofconstruction, the characteristic curves produced by one such section asshown in FIG. 29 is changed to that shown in FIG. 30. This change iscaused by retroreflected light patterns produced from the effectivelysuperimposed curves from each such single section. Observe, that, justas in the case of FIG. 29, a small region of I percent reflexreflectivity exits near the origin, and that the percentage (orefficiency) of retroreflected light drops as one proceeds radiallyoutwardly away from the origin.

In FIG. 31 is shown in polar coordinates a family of curves ofretroreflected light for one embodiment, such as the reflector of FIG.22, of a particular wide angle retroreflective surface which is sidereflective in one direction only. Here, (see FIG. 22 shaded lines), thestandard type retroreflective facets are opaqued together with the wideangle facets which retroreflect to wards one side or direction, leavingonly side reflective facets for one direction only. Observe that 100percent retroreflectivity is obtained in this embodiment at two smallregions each inclined at an angle of about [5 with respect to thehorizontal and at an angle of about 35 with respect to the vertical. Thepercentage of retroreflectivity decreases with increasing angles ofincident light from 35. Observe that retroreflectance is here achievedover a wide range of from about 6 through about 77, in the particularembodiment shown in FIG. 31, but is more efficient in the range fromabout 15 to 55 in terms of percentages of retroreflected light, and ismost efficient between about 30 and 40.

When a reflector whose reflected light pattern is as illustrated in, forexample, FIGS. 29 and 30, is mounted upon the side of a revolving wheelmember parallel to the center plane thereof only slight relativevariations in the intensity of retroreflected light occur from thestandpoint of a viewer situated within the retroreflective viewing angleassociated with such a reflector, regardless of reflector position onthe wheel member, so that, as a wheel rotates, a more or less constantsource of reflected light is viewed by such a viewer. On the other hand,when a reflector whose reflected light pattern is as illustrated in FIG.31 is mounted upon the side ofa wheel member parallel to the centerplane thereof, and such wheel member is rotated, the light patternemitted retroreflectively by the reflector is only intermittently seenby a viewer situated within retroreflective viewing angles of thereflector body. As a consequence, such viewer sees a flashing source ofretroreflected light caused by the fact that the retroreflective surfacemoves into and out of such viewer's line of vision on a continuing andregular basis as the wheel ro tates. A wide angle, side viewable,retroreflective surface mounted on a rotating wheel as indicated thusproduces a characterisic flashing effect not possible with a standardreflective surface mounted substantially par allel to the center planeof the associated wheel member.

If one equips, for example, each wheel 81A and 82A of a bicycle 80A witha single side viewable, wide angle, retroreflective reflector 83A and84A respectively (see FIGS. 18, 19 and 32) in such a manner that aperpendicular 85A and 86 to the center plane (not shown) of each wheel81A and 82A, respectively, is perpendicular to each such wide anglereflector 83A and 84A on each wheel, each such reflector 83A and 84A isside viewable over a relatively wide viewing angle, such as angles 87and 88 in FIG. 32. Commonly, such an included angle 87 or 88 can be fromabout tot) to on either side of such a vertical or perpendicular 85A or86, relative to the center plane of each wheel member 81A or 82A of thebicycle A. For example, refer ring to FIG. 19, reflector 83A is adaptedto retroreflect incident light up to about 70 on one side of vertical B(see FIG. 32). A similar situation prevails upon the respective oppositesides of the wheels 81A and 82A of bicycle 80A.

The manner in which light is retroreflected from such a wheel 81A or 82Ahaving a reflector 83A or 84A. respectively. so mounted thereon isillustrated, for example. in FIG. 21. Light within a viewing angle of.for ex ample. from about to for such a reflector is re troreflccted toone side of such a wheel in a transversely continuously expandingthree-dimensional viewing zone 89 which revolvably moves through spaceat a rate corresponding to the associated wheel rotational speed. As theZone 89 sweeps past an eye 90 of a viewer angularly so situtated as tobe within the vicw ing zone 87. the reflected light in the zone isviewable by eye 90 for a brief interval of time. producing a flashingeffect upon eye 90. It will be appreciated that. for any givenwheellreflector combination. the position of the zone 89 is dependentupon the orientation and the angle a given reflector is mounted upon itsassociated wheel member. Preferably. these variables for a givenwheellreflector assembly are so chosen that a minimum area ofpotentially constant or continuous retrorefleetion exists relative tothe side of a given wheel of a wheeli'reflector assembly of thisinvention as such given wheel rotates; in other words. the angle ofpotential overlap produced near the region of a projected wheel axis asa Zone 89 rotates is minimized.

Because of the peculiar. unique retroreflective light patterns generatedby wide angle reflectors. they produce distinct flashing effects whenmounted on a rotating-wheel member not common to standard reflectorsmounted substantially parallel to the center plane of the associatedwheel member. While the present invention may be practiced usingreflectors which contain one or more combinations of standard and wideangle reflector areas. as in a single molded reflector body. a givenreflector body for use in the present invention always contains at leastone wide angle reflector area. regardless of how such body is mounted onthe side of an associated wheel member.

To secure a reflector containing a wide angle retroreflective area offacets (surfaces) to a spoked wheel member. spoke mounting means isprovided. Usually. a reflector has a backing member or base member. suchas member 41 of reflector 35 (FIG. 31. This backing member 4] isconventionally providable with any one or more of a variety of spokemounting means adapted for mounting a reflector assembly to a spokedwheel member of the type commonly found on bicycles and the like.including clips (see FIGS. 7 and 8) or snaps (see FIG. 20).

FIG. 33 illustrates the relationship between a wheel member and areflector used in this invention. Thus. a wheel member (not detailed)characteristically has a center plane 92 and a reflector such asreflector 93 of FIG. 22. is mounted on such wheel member so as to besubstantially parallel to the center plane 92. Each wide anglereflective area 94 and 95 therein (not detailed in F1033) has a midregion of maximum retroreflectance which occurs generally as straightline. such as lines 96 and 97. Each line 96 and 97 projects obliquelyoutwardly from the reflective surface of reflector 93 at an angle 99 and100. respectively, somewhere in the range from about 30 to 70 withrespect to a perpendicular 98 to reflector 93. In any given embodiment.the angles 99 and 100 are determined by three primary variables.reflector pin angle. angular position of a reflector relative to a\vheels center plane. and reflector orientation relative to a wheel'scenter plane. In the present invention. a particular flattened wideangle reflector area mounted on the side of a wheel is so positioned asto be substantially parallel to the wheel center plane with theflattened face of the wide angle reflector area facing generallyoutwardly and sidewards from the wheel. Owing to wheel construction. asthose sl'i e'l in the art will appreciate. as a practical matter. it issometimes difficult to make the wide angle reflector area extend trulyparallely to the center plane of the associated wheel member as the wideangle reflector area is mounted on the side of a wheel member. Thus. forexample. a spoked wheel member of the type commonly used on two wheeledvehicles, such as bicycles, or the like, can tend to produce a slightangular deviation of the flattened face of a wide angle reflector arearelative to the center plane of a wheel as the wide angle reflectorincorporating such area is mounted on such wheel member so that theflattened reflector face (with the wide angle reflector areatherebehind) is not truly parallel to the center plane of the wheel. Forthis reason. it is possible that a given wide angle reflector area rela'tive to a given associated wheel member may be inclined at an anglerelative to the center plane of such wheel. This angle may be as much asabout 20, though preferably such an angular deviation is not more thanabout tlS", and more preferably is not more than about iltl" at most.Most preferably. this wide angle reflector area is substantiallyparallel to the center plane in practicing this invention.

In a practical use situation as those skilled in the art willappreciate. the exact attitude and angular position of a particular wideangle reflector area relative to the side of a particular wheel membercenter plane is determined by a number of variables. It is a distinctfeature of this invention that the special attributes of a system ofthis invention as explained herein are not particularly altered forpurposes of the present invention by such non planar angular deviationsasjust indicated be tween a wide angle reflector area and its flattenedfron tal face relative to the center plane of an associated wheelmember.

A reflector 93' which is like reflector 93 (see FIG. 33) can be somounted relative to center plane 92 that a straight line such as 96'from one area such as 94 thereof (see FIG. 22) extends generallyparallelly to any plane. such as plane 10], which passes through thecenter 102 of said wheel member. and center plane 92 thereof. and whichalso is perpendicular to said center plane 92.

Reflector 93 has a first and a second wide angle reflective areatherein. Each has a mid region of maximum retroreflectance lying along astraight line which projects obliquely outwardly from the reflective surface of reflector 93 at a substantially identical angle with respect toa perpendicular to said reflector. though these angles may differ ifdesired. Each straight line extends in a diverging direction from theother. but these lines could extend in the same direction if de sired.Both such lines in reflector 93 lie in substantially the same plane. butthey need not, if desired. A given reflector can contain more than twowide angle areas, if desired.

In summary. the present invention relates to apparatus for producing alight flashing effect. The invention utilizes a retroreflectivereflector which is characterized by having a generally flattenedconfiguration. a wide angle reflective area therein. and a mid region ofmaximum retroreflectance for said wide angle reflective area therein.This reflective area of maximum retrorefleetance occurs generally alonga straight line which projects obliquely outwardly from the reflectivesurface of said reflector at an angle in the range from about to 70(preferably about 30 to 60) perpendicular to said reflector. Wheelmembers used in this invention can be of any convenient type.

The invention involves the steps of mounting such a reflector on oneside of a wheel so that the wide angle reflective area thereof extendsgenerally parallelly to the center plane of said wheel member, and thenrotating said resulting wheel member in the presence of light incidenton said one side. The apparatus of this invention involves the assemblyof such a reflector being so mounted to one side of a wheel member.

In one mode, such a reflector is so mounted that such straight lineprojects generally parallelly to any plane which passes through thecenter of such wheel member and which also is perpendicular to suchcenter plane. In such mode or another, one can, and preferably does,employ a second such wide angle reflective area along with the first,which can be in the same reflective body or a second. Thus, a reflectorcan have both a first and a second wide angle reflective area therein.Such second area has a mid region of maximum retroreflectance accordinggenerally along a second straight line which projects obliquelyoutwardly from the reflective surface of such reflector at a secondangle preferably in the range from about 30 to 60. This second angle canbe substantially equal to said first angle with respect to aperpendicular to said reflector, or such second angle can be differentfrom said first angle.

The said second straight line can extend in a diverging direction fromsaid first line, and can lie substantially in the same plane as saidfirst line. Preferably, one uses a spoked wheel member, and thecombination of wheel and reflector(s) is operatively mounted in abicycle or the like. Preferably a wheel member has at least one suchreflector on each side thereof, which may be mounted back-to-back, forexample, across the wheel spokes.

Other and further embodiments and variations of the present inventionwill become apparent to those skilled in the art from a reading of thepresent specification taken together with the drawings and no unduelimitations are to be inferred or implied from the present disclosure.

We claim:

1. An assembly for producing a light flashing effect comprising incombination A. a rotatable wheel member having a wheel axis.

B. a reflector unit having at least one region comprised of transparentsolid material and having a region axis normal thereto, said regionhaving formed therein a group of cube corner reflector elements, suchelements each having a central optical axis, each respective suchoptical axis being both disposed substantially parallel to therespective such optical axes of the other such elements in said group,and inclined at a predetermined angle relative to said region axis, saidregion being retroreflective of light directed thereon at least over anangle of from about 20 to relative to said re gion axis in the directionof said predetermined an C. mounting means to mount said reflectorfixedly to a side portion of said wheel member,

D. said wheel member, said reflector and said mounting means coactingtogether so that, when said wheel is rotated, said reflector is adaptedto retroreflect light intermittently so as to produce a flashing lightsignal viewable within a viewing angle of at least about 20 to 70relative to said wheel axis once during each 360 of wheel rotation.

2. The assembly of claim 1 wherein said reflector contains two suchregions, said wheel member; said reflector and said mounting meanscoacting together so that, when said wheel is rotated, said reflector isadapted to retro-reflect light intermittently so as to produce twoflashing light signals, each one of said signals being viewable within aviewing angle of at least about 20 to 70 relative to said wheel axisonce during each 360 of wheel rotation.

3. The assembly of claim 2 wherein the respective region axes aresubstantially parallel to each other.

4. The assembly of claim 3 wherein said reflector contains a thirdregion, said third region being generally retro-reflective of lightdirected thereon at least over an angle of about 30 about its regionaxis, said area having a group of cube corner reflector elements formedtherein, the respective optical axes of said reflector elements beingdisposed substantially parallel to its said region axes, all region axesof said reflector being substantially parallel to each other, saidreflector having a combined zone of reflectorization which is at leastabout measured transversely in one direction relative to said regionaxes.

5. The assembly of claim 1 wherein said wheel mem ber is spoked.

1. An assembly for producing a light flashing effect comprising incombination A. a rotatable wheel member having a wheel axis, B. areflector unit having at least one region comprised of transparent solidmaterial and having a region axis normal thereto, said region havingformed therein a group of cube corner reflector elements, such elementseach having a central optical axis, each respective such optical axisbeing both disposed substantially parallel to the respective suchoptical axes of the other such elements in said group, and inclined at apredetermined angle relative to said region axis, said region beingretroreflective of light directed thereon at least over an angle of fromabout 20* to 70* relative to said region axis in the direction of saidpredetermined angle, C. mounting means to mount said reflector fixedlyto a side portion of said wheel member, D. said wheel member, saidreflector and said mounting means coacting together so that, when saidwheel is rotated, said reflector is adapted to retro-reflect lightintermittently so as to produce a flashing light signal viewable withina viewing angle of at least about 20* to 70* relative to said wheel axisonce during each 360* of wheel rotation.
 1. An assembly for producing alight flashing effect comprising in combination A. a rotatable wheelmember having a wheel axis, B. a reflector unit having at least oneregion comprised of transparent solid material and having a region axisnormal thereto, said region having formed therein a group of cube cornerreflector elements, such elements each having a central optical axis,each respective such optical axis being both disposed substantiallyparallel to the respective such optical axes of the other such elementsin said group, and inclined at a predetermined angle relative to saidregion axis, said region being retroreflective of light directed thereonat least over an angle of from about 20* to 70* relative to said regionaxis in the direction of said predetermined angle, C. mounting means tomount said reflector fixedly to a side portion of said wheel member, D.said wheel member, said reflector and said mounting means coactingtogether so that, when said wheel is rotated, said reflector is adaptedto retro-reflect light intermittently so as to produce a flashing lightsignal viewable within a viewing angle of at least about 20* to 70*relative to said wheel axis once during each 360* of wheel rotation. 2.The assembly of claim 1 wherein said reflector contains two suchregions, said wheel member; said reflector and said mounting meanscoacting together so that, when said wheel is rotated, said reflector isadapted to retro-reflect light intermittently so as to produce twoflashing light signals, each one of said signals being viewable within aviewing angle of at least about 20* to 70* relative to said wheel axisonce during each 360* of wheel rotation.
 3. The assembly of claim 2wherein the respective region axes are substantially parallel to eachother.
 4. The assembly of claim 3 wherein said reflector contains athird region, said third region being generally retro-reflective oflight directed thereon at least over an angle of about 30* about itsregion axis, said area having a group of cube corner reflector elementsformed therein, the respective optical axes of said reflector elementsbeing disposed substantially parallel to its said region axes, allregion axes of said reflector being substantially parallel to eachother, said reflector having a combined zone Of reflectorization whichis at least about 80* measured transversely in one direction relative tosaid region axes.